Elitedesk 705 G5 SFF will not boost past 3.8ghz

[Jeffcos]

HI, I have an Elitedesk 705 G5 SFF that will absolutely positively NOT boost to the 4.2 ghz that AMD says it is capable of.

Clean windows 10 install, all drivers installed and current, bios is current. Machine can be pegged at 100% CPU across all cores and it refuses to go beyond 3.8 although apparently at some point it did go to 4.0 according to the program Quick CPU. It usually is between 3.7 and 3.8 at 100% cpu but it will lower to 2.69 when it's idle.

CPU temperature is average 57c and max was 71c, probably when it was at 4.0 ghz briefly. It's usually shy of 40w power consumption at 3.8 ghz.

Am I missing something? I don't know what HP has set the TDP max to but it isn't even hitting 45w. Temperatures are well under the maximum. 

The case is open, that's the only thing that I might consider to be abnormal. Would that affect the cpu boost?

Thank you in advance.

[banhien]

@Jeffcos 

It should go to 4.2GHz but only few nano seconds. Can Quick CPU program give down to that level ?

Regards.

[Jeffcos]

I looked at this information Here and it suggests that it will boost until thermal conditions throttle it back so I'm not sure where you are getting your info from. Afaik Intel boost works the same way where it will boost for a significant amount of time, at least a few seconds.